S-Video
About S-Video, more commonly known as Separate Video, and sometimes incorrectlyneeded referred to as Super Video1 and also known as Y/C, is an analog video signal that carries a video data as two separate signals: lumen (luminance) and chroma (color). This differs from composite video, which carries picture information as a single lower-quality signal, and component video, which carries picture information as three separate higher-quality signals. S-Video carries standard definition video (typically at 480i or 576i resolution), but does not carry audio on the same cable. The 4-pin mini-DIN connector (shown at right) is the most common of several S-Video connector types. Other S-Video connector variants include 7-pin locking "dub" connectors used on many professional S-VHS machines, and dual "Y" and "C" BNC connectors, often used for S-Video patch bays. Early Y/C video monitors often used RCA connectors that were switchable between Y/C and composite video input. Though the connectors are different, the Y/C signals for all types are compatible. 7-pin mini-DIN A 7-pin mini-DIN socket. * Nonstandard 7-pin mini-DIN connectors (variant is called "7P") are used on laptops and video cards. A 7-pin socket accepts a 4-pin plug, but not vice versa. The S-Video signals are available on the four matching pins as before. Of the other three pins, one carries a CVBS composite video signal for non-S-Video displays. * The pin out is as follows (pins are numbered from left to right in the diagram above; 4,7,3 on the top row, and 2,6,5,1 on the bottom row. Thus, the pins that match the 4-pin variant are numbered 1–4 as before). 1 - S-Video Luminance Ground 2 - S-Video Chrominance Ground 3 - S-Video Luminance Signal 4 - S-Video Chrominance Signal 5 - Composite Video Ground 6 - (No Connection) 7 - Composite Video Signal Usage S-Video is commonly used throughout the world with relative popularity. It is found on consumer TVs, DVD players, high-end video cassette recorders, digital TV receivers, DVRs, game consoles, and graphics cards. It has been replaced by component video and digital video standards, such as DVI and HDMI. S-Video cables are used for computer-to-TV output for business or home use. Because it is very simple to convert S-Video to composite signal (just the physical merging of the two through a filter capacitor is required), many electronics retailers offer converter adaptors for signal conversion. Conversion will not improve image quality, but will allow connecting to otherwise incompatible devices. Converting composite signal to S-Video is harder, because once Luminance and Color are merged, it is hard to separate them while minimizing loss. High quality comb filters are commonly used to separate the signals. Due to a lack of bandwidth, S-Video connections are generally not considered suitable for high-definition video signals. As a result, HD sources are generally connected to a monitor by way of analog component video or wideband digital methods (usually HDMI or DVI). However, when using older monitors with S-Video but without HDMI and DVI, some graphics cards have full display (including bootup display) with HDMI, DVI, and S-Video and partially full display (displaying only after the OS boots up) with component and composite. So in this case, S-Video works well, as it allows the user to see the display in the event that they need to adjust settings in the CMOS. The situation with VCRs is a bit unusual: the common S-Video connector was designed for Super VHS and Hi8 VCRs as a high-bandwidth video connection and has been used for the same purpose on a great number of other consumer devices, coming into greatest prominence with the rise of the DVD format. Many digital (and all Hi-8 and S-VHS-C camcorders) support S-Video out as well. Standard VHS VCRs do not put out a high enough resolution signal to saturate an S-Video connection, and therefore most such units (even those in combination units with DVD players, which commonly use S-Video or component outputs) require the output from the VHS deck to go through a composite video or RF connection. In many EU countries, S-Video is less common because of the dominance of SCART, which allows RGB quality and is required to be on every TV. It is not usual to find S-Video outputs on equipment such as DVD players, although the player may output S-Video over SCART, but the actual TV may not be compatible with S-Video signals and so would just show a black and white image.3. In this case it is possible to modify the SCART adapter cable to make it work 4. Games consoles usually do not output S-Video either due to the dominance of SCART and the better RGB quality, whilst in the US and other non SCART countries there is S-Video but no RGB. The Nintendo 64 however was an exception: NTSC models could not output S-Video, but with modification they could output RGB, while PAL models could output S-Video but not RGB, despite that being the easiest way to connect if done via SCART. Links Category:Computers and Networking